The invention relates to a sheet-like waterproof sealing web, which is suitable for use in construction above and under ground.
It is known to use plastic sheets as sealing materials by placing the sheet-like webs in overlapping manner on a substrate, whilst placing a strip or tape of pressure-sensitive profiled adhesive compound, e.g. butyl rubber between the sheets for joining the webs in the overlapping area. The necessary adhesive tape is placed between two layers of non-adhering protective foil, e.g. siliconized paper, for transportation, handling and during storage.
German Offenlegungsschrift No. 25 10 162 describes a sheet-like rubber sealing material which is provided with an adhesive tape during its manufacture. One adhesive tape is applied along one longitudinal edge on the upper surface and a further adhesive tape is provided at the opposite longitudinal edge at the upper side of the web. The adhesive tapes may be protected by a silicone paper.
The sheets of sealing material can also be welded by solvents or by heating. However, the application of such sealing webs is very complicated and time-consuming and even slight impressions when inserting the adhesive tape or during welding in the overlapping area can lead to an untight joint. German Offenlegungsschrift No. 1 621 939 discloses sealing materials comprising a flexible film laminated with a pressure-sensitive adhesive and sealing compound. The preferred material for the sealing compound is a bitumen/rubber composition. This material is also applied in web-like overlapping manner in such a way that the adhesive sealing compound adheres to the substrate to be sealed and is protected by the covering film. In the overlapping area, the adhesive and sealing compound of the upper web rests on the covering film of the lower web, so that a bond is obtained between the compound and the film. If the webs are not laid completely smoothly, e.g. due to an unevenness of the substrate or in the case of stresses due to temperature fluctuations, there can be an incomplete bond between the sealing compound and the film in the overlapping area and capillaries can form through which water can penetrate.
U.S. Pat. No. 4,172,830 discloses a modification of the above material according to which the pressure-sensitive adhesive membrane is laminated with a flexible support sheet with a non-adhering outer surface. A minor portion of the pressure-sensitive adhesive membrane along one edge of the sheet-like material is covered with a flexible film which is non-adherent on both surfaces and may therefore be removed when applying the sealing material to a substrate. An overlapping application will therefore result in an adhesive to adhesive bonding. Due to its non-adherent properties it is not possible to apply a further adhesive material on top of the sealing material. In addition, it is not possible to use bitumen-coated sealing webs everywhere, for example they are not suitable for laying on certain thermal insulating materials which are being increasingly used in the completion of interiors and for roof coverings.